BACKGROUND: The meagre, Argyrosomus regius, is a large coastal predatory fish inhabiting waters from the north-eastern Atlantic and Mediterranean Sea, where it is targeted by commercial and recreational fisheries. Previous genetic studies have found an unexpectedly high population differentiation not only between the Atlantic and the Mediterranean, but also along the Atlantic coast. However, the reasons underpinning this genetic barrier remained unclear. Likewise, even though the species is amongst the world\'s largest marine teleosts, knowledge about its movement ecology and migratory behaviour remains notably scarce, and primarily reliant on fisheries-dependent data.
METHODS: In this study, we used a combination of acoustic telemetry and pop-up satellite archival tags to investigate the movements of 22 adult meagre (70-143 cm total length) along the Southwestern coast of the Iberian Peninsula.
RESULTS: Our results strongly suggest that the previously reported genetic differentiation is not maintained by limited adult dispersal/movement, as hypothesized. On the contrary, we documented some of the longest individual annual migrations ever recorded for a coastal teleost, up to > 2000 km, with frequent back-and-forth movements between the West and Southern Iberian coasts. Moreover, their detected regional movement patterns support the existence of a marked seasonal behavioural shift, with individuals being less active and moving to deeper waters during winter, and are consistent with spawning philopatry associated to their summer reproductive movements. Finally, we identified putative aggregation areas that may harbour important feeding/overwintering grounds.
CONCLUSIONS: These findings shed new light on the movement and behaviour patterns of meagre that may be of particular importance for the conservation and spatial management of this species throughout its range, and open the door to further research on functional connectivity.

Understanding fish movement is critical in determining the spatial scales in which to appropriately manage wild populations. Genetic markers provide a natural tagging approach to assess the degree of gene flow and population connectivity across a species distribution. We investigated the genetic structure of black bream Acanthopagrus butcheri across its entire distribution range in Australia, as well as regional scale gene flow across south-eastern Australia by undertaking a comprehensive analysis of the populations in estuaries across the region. We applied genome-wide sampling of single-nucleotide polymorphism (SNP) markers generated from restriction site-associated DNA sequencing. Genetic structure and potential gene flow was assessed using principal component analyses and admixture analyses (STRUCTURE). Using 33,493 SNPs, we detected broad scale genetic structuring, with limited gene flow among regional clusters (i.e. Western Australia, South Australia and western Victoria; and eastern Victoria, Tasmania and New South Wales). This is likely the result of unsuitable habitats, strong ocean currents (e.g. the Leeuwin Current and the East Australian Current), large water bodies (e.g. Bass Strait) and known biogeographical provinces across the continent. Local-scale genetic structuring was also identified across the south-eastern Australian estuaries sampled, reflecting that the coexistence of both migratory and resident individuals within populations (i.e. partial migration), and the movement of fish into coastal waters, still results in strong philopatry across the region. Instances of movement among estuaries at this spatial scale were primarily found between adjacent estuaries and were likely attributed to lone migrants utilising inshore coastal currents for movement beyond nearby habitats. Targeting SNP markers in A. butcheri at this continental scale highlighted how neither spatial proximity of estuaries nor black bream\'s ability to move into coastal waters reflects increased gene flow. Overall, our findings highlight the importance of location-specific management.

The response to climate change in highly dimorphic species can be hindered by differences between sexes in habitat preferences and movement patterns. The Antarctic fur seal, Arctocephalus gazella, is the most abundant pinniped in the Southern Hemisphere, and one of the main consumers of Antarctic krill, Euphausia superba, in the Southern Ocean. However, the populations breeding in the Atlantic Southern Ocean are decreasing, partly due to global warming. Male and female Antarctic fur seals differ greatly in body size and foraging ecology, and little is known about their sex-specific responses to climate change. We used satellite tracking data and Earth System Models to predict changes in habitat suitability for male and female Antarctic fur seals from the Western Antarctic Peninsula under different climate change scenarios. Under the most extreme scenario (SSP5-8.5; global average temperature +4.4°C projected by 2100), suitable habitat patches will shift southward during the non-breeding season, leading to a minor overall habitat loss. The impact will be more pronounced for females than for males. The reduction of winter foraging grounds might decrease the survival of post-weaned females, reducing recruitment and jeopardizing population viability. During the breeding season, when males fast on land, suitable foraging grounds for females off the South Shetland Islands will remain largely unmodified, and new ones will emerge in the Bellingshausen Sea. As Antarctic fur seals are income breeders, the foraging grounds of females should be reasonably close to the breeding colony. As a result, the new suitable foraging grounds will be useful for females only if nearby beaches currently covered by sea ice emerge by the end of the century. Furthermore, the colonization of these new, ice-free breeding locations might be limited by strong female philopatry. These results should be considered when managing the fisheries of Antarctic krill in the Southern Ocean.
La resposta al canvi climàtic en espècies amb dimorfisme sexual pot veure\'s dificultada per les diferències entre sexes respecte a les seves preferències d\'ús de l\'hàbitat i els seus patrons de moviment. L\'os marí antàrtic (Arctocephalus gazella), és el pinnípede més abundant a l\'Hemisferi Sud i un dels principals consumidors de krill antàrtic, (Euphausia superba), a l\'Oceà Antàrtic. No obstant això, les poblacions que es reprodueixen al sector Atlàntic de l\'Oceà Antàrtic estan disminuint, en part a causa de l\'escalfament global. Els mascles i les femelles de l\'os marí antàrtic difereixen considerablement en la seva mida corporal i ecologia tròfica, i es té poc coneixement sobre les seves respostes específiques al canvi climàtic. En aquest estudi hem utilitzat dades de seguiment per satèl·lit i models del Sistema Terrestre per predir els canvis en la idoneïtat de l\'hàbitat per als mascles i les femelles d\'os marí antàrtic de la Península Antàrtica Occidental sota diferents escenaris de canvi climàtic. Sota l\'escenari més extrem (SSP5-8.5; temperatura mitjana mundial +4.4°C prevista per a 2100), les zones d\'hàbitat idoni es desplaçaran cap al sud durant l\'època d\'hivernada (no reproducció), provocant una lleugera pèrdua d\'hàbitat idoni. Tot i això, l\'impacte serà més pronunciat per a les femelles que per als mascles. Aquesta reducció dels territoris d\'alimentació durant l\'hivern podria disminuir la supervivència de les femelles postdeslletades, reduint-ne el reclutament i posant en perill la viabilitat de la població. Durant l\'època de cria, quan els mascles es troben majoritàriament en dejú a terra, els territoris d\'alimentació idonis per a les femelles al voltant de les Illes Shetland del Sud romandran en gran part sense modificar-se, i n\'emergiran de nous al mar de Bellingshausen. Com que les femelles d\'os marí antàrtic es continuen alimentant durant la cria, els territoris d\'alimentació de les femelles han d\'estar raonablement a prop de la colònia de cria. Com a resultat, aquestes noves zones d\'alimentació seran útils només si les platges properes, actualment cobertes de gel marí, emergeixen al llarg del segle. A més, la colonització d\'aquests nous llocs de reproducció lliures de gel podria veure\'s limitada per la forta filopatria de les femelles. Aquests resultats haurien de tenir-se en compte en la gestió de les pesqueries de krill a l\'Oceà Antàrtic.
La resposta al canvi climàtic en espècies amb dimorfisme sexual pot veure\'s dificultada per les diferències entre sexes respecte a les seves preferències d\'ús de l\'hàbitat i els seus patrons de moviment. L\'os marí antàrtic (Arctocephalus gazella), és el pinnípede més abundant a l\'Hemisferi Sud i un dels principals consumidors de krill antàrtic, (Euphausia superba), a l\'Oceà Antàrtic. No obstant això, les poblacions que es reprodueixen al sector Atlàntic de l\'Oceà Antàrtic estan disminuint, en part a causa de l\'escalfament global. Els mascles i les femelles de l\'os marí antàrtic difereixen considerablement en la seva mida corporal i ecologia tròfica, i es té poc coneixement sobre les seves respostes específiques al canvi climàtic. En aquest estudi hem utilitzat dades de seguiment per satèl·lit i models del Sistema Terrestre per predir els canvis en la idoneïtat de l\'hàbitat per als mascles i les femelles d\'os marí antàrtic de la Península Antàrtica Occidental sota diferents escenaris de canvi climàtic. Sota l\'escenari més extrem (SSP5-8.5; temperatura mitjana mundial +4.4°C prevista per a 2100), les zones d\'hàbitat idoni es desplaçaran cap al sud durant l\'època d\'hivernada (no reproducció), provocant una lleugera pèrdua d\'hàbitat idoni. Tot i això, l\'impacte serà més pronunciat per a les femelles que per als mascles. Aquesta reducció dels territoris d\'alimentació durant l\'hivern podria disminuir la supervivència de les femelles postdeslletades, reduint-ne el reclutament i posant en perill la viabilitat de la població. Durant l\'època de cria, quan els mascles es troben majoritàriament en dejú a terra, els territoris d\'alimentació idonis per a les femelles al voltant de les Illes Shetland del Sud romandran en gran part sense modificar-se, i n\'emergiran de nous al mar de Bellingshausen. Com que les femelles d\'os marí antàrtic es continuen alimentant durant la cria, els territoris d\'alimentació de les femelles han d\'estar raonablement a prop de la colònia de cria. Com a resultat, aquestes noves zones d\'alimentació seran útils només si les platges properes, actualment cobertes de gel marí, emergeixen al llarg del segle. A més, la colonització d\'aquests nous llocs de reproducció lliures de gel podria veure\'s limitada per la forta filopatria de les femelles. Aquests resultats haurien de tenir-se en compte en la gestió de les pesqueries de krill a l\'Oceà Antàrtic.

Individuals delay natal dispersal for many reasons. There may be no place to disperse to; immediate dispersal or reproduction may be too costly; immediate dispersal may mean that the individual and their relatives miss the benefits of group living. Understanding the factors that lead to the evolution of delayed dispersal is important because delayed dispersal sets the stage for complex social groups and social behavior. Here, we study the evolution of delayed dispersal when the quality of the local environment is improved by greater numbers of individuals (e.g., safety in numbers). We assume that individuals who delay natal dispersal also expect to delay personal reproduction. In addition, we assume that improved environmental quality benefits manifest as changes to fecundity and survival. We are interested in how do the changes in these life-history features affect delayed dispersal. We use a model that ties evolution to population dynamics. We also aim to understand the relationship between levels of delayed dispersal and the probability of establishing as an independent breeder (a population-level feature) in response to changes in life-history details. Our model emphasizes kin selection and considers a sexual organism, which allows us to study parent-offspring conflict over delayed dispersal. At evolutionary equilibrium, fecundity and survival benefits of group size or quality promote higher levels of delayed dispersal over a larger set of life histories with one exception. The exception is for benefits of increased group size or quality reaped by the individuals who delay dispersal. There, the increased benefit does not change the life histories supporting delay dispersal. Next, in contrast to previous predictions, we find that a low probability of establishing in a new location is not always associated with a higher incidence of delayed dispersal. Finally, we find that increased personal benefits of delayed dispersal exacerbate the conflict between parents and their offspring. We discuss our findings in relation to previous theoretical and empirical work, especially work related to cooperative breeding.

Eradicating invasive predators from islands can result in substantial recovery of seabirds, but the mechanisms that drive population changes remain poorly understood. Meta-analyses have recently revealed that immigration is surprisingly important to the recovery of philopatric seabirds, but it is not known whether dispersal and philopatry interact predictably to determine rates of population growth and changes of distribution. We used whole-island surveys and long-term monitoring plots to study the abundance, distribution, and trends of 4 burrowing seabird species on Macquarie Island, Australia, to examine the legacy impacts of invasive species and ongoing responses to the world\'s largest eradication of multiple species of vertebrates. Wekas (Gallirallus australis) were eradicated in 1988; cats (Felis catus) in 2001; and rabbits (Oryctolagus cuniculus), black rats (Rattus rattus), and mice (Mus mus) in 2011-2014. We compared surveys from 1976-1979 and 2017-2018 and monitoring from the 1990s and 2000s onward. Antarctic prions (Pachyptila desolata) and white-headed petrels (Pterodroma lessonii) increased ∼1% per year. Blue petrels (Halobaena caerulea) and gray petrels (Procellaria cinerea) recolonized following extirpation from the main island in the 1900s but remained spatially and numerically rare in 2018. However, they increased rapidly at 14% and 10% per year, respectively, since cat eradication in 2001. Blue and gray petrel recolonization occurred on steep, dry, west-facing slopes close to ridgelines at low elevation (i.e., high-quality petrel habitat). They overlapped <5% with the distribution of Antarctic prion and white-headed petrels which occurred in suboptimal shallow, wet, east-facing slopes at high elevation. We inferred that the speed of population growth of recolonizing species was related to their numerically smaller starting size compared with the established species and was driven by immigration and selection of ideal habitat.
Patrones de recuperación en aves marinas existentes y extirpadas después de la mayor erradicación mundial de multidepredadores Resumen La erradicación de depredadores invasores en las islas puede derivar en la recuperación sustancial de aves marinas, aunque entendemos muy poco los mecanismos que causan los cambios poblacionales. Los metaanálisis recientes han revelado que la inmigración es de gran importancia para la recuperación de aves marinas filopátricas, aunque no sabemos si la dispersión y la filopatría interactúan de forma predecible para poder determinar las tasas de crecimiento poblacional y los cambios en la distribución. Aplicamos censos de isla completa y parcelas de monitoreo a largo plazo para estudiar la abundancia, distribución y tendencias de cuatro especies de aves marinas cavadoras en la Isla Macquarie, Australia, para analizar los impactos heredados de las especies invasoras y la respuesta continua a la mayor erradicación mundial de varias especies de vertebrados. El rascón weka (Gallirallus australis) se erradicó en 1988; los gatos (Felis catus) en 2001; y los conejos (Oryctolagus cuniculus), ratas (Rattus rattus) y ratones (Mus mus) entre 2011 y 2014. Comparamos los censos de 1976–1979 y 2017–2018 y el monitoreo realizado en los 90s y del año 2000 en adelante. El pato petrel antártico (Pachyptila desolata) y el petrel cabeciblanco (Pterodroma lessonii) incrementaron ∼1% por año. El petrel azulado (Halobaena caerulea) y la pardela gris (Procellaria cinerea) recolonizaron la isla después de su extirpación en la década de 1900, pero todavía eran especies raras espacial y numéricamente en 2018. Sin embargo, esta especie incrementó rápidamente en un 14% y 10% por año respectivamente desde que se erradicaron los gatos en 2001. La recolonización ocurrió desde las laderas empinadas, secas y con orientación al oeste en los sistemas montañosos de baja elevación (es decir, hábitats de gran calidad para los petreles). La distribución del petrel azulado y la pardela gris ocurrió en laderas someras subóptimas y húmedas con orientación al este a altas elevaciones. Esta distribución se traslapó menos del 5% con la del pato petrel antártico y la del petrel cabeciblanco. Inferimos que la velocidad del crecimiento poblacional de las especies que recolonizaron estuvo relacionada con el menor tamaño inicial en comparación con las especies establecidas y fue causada por la inmigración y la selección del hábitat ideal.
消灭岛屿上的入侵捕食者可以帮助海鸟大幅恢复, 但目前对种群变化的驱动机制仍知之甚少。近期的一项荟萃分析表明, 鸟类个体迁入对归巢海鸟的恢复具有惊人的重要作用, 但人们还不知道扩散和归巢行为是否存在可预测的相互作用, 来决定种群增长率和分布范围变化。本研究利用全岛调查和位点长期监测研究了澳大利亚麦格理岛上四种穴居海鸟的丰度、分布和种群趋势, 以分析入侵物种的遗留影响以及这些海鸟对世界上最大规模的多种脊椎动物消灭行动的持续响应。该地区于 1988 年消灭了新西兰秧鸡 (Gallirallus australis); 2001 年消灭了猫 (Felis catus); 并在 2011–2014 年消灭了兔子 (Oryctolagus cuniculus) 、黑鼠 (Rattus rattus) 和小鼠 (Mus mus) 。我们比较了 1976–1979 年和 2017–2018 年的调查以及 20 世纪 90 年代和 21 世纪以来的监测。结果表明, 南极锯鹱 (Pachyptila desolata) 和白头海燕 (Pterodroma lessonii) 每年增长 ~1% 。蓝海燕 (Halobaena caerulea) 和灰海燕 (Procellaria cinerea) 于 20 世纪在主岛的消灭行动后重新定殖, 但直到 2018 年在空间和数量上仍然较为稀少。不过, 自 2001 年消灭掉猫以来, 它们分别以每年 14% 和 10% 的速度迅速增加。重新定殖区主要在靠近山脊线陡峭、干燥、朝西的低海拔斜坡上 (即海燕高质量栖息地) 。蓝海燕和灰海燕分布在次优的平缓、潮湿、朝东的较高海拔斜坡上, 与南极锯鹱和白头海燕分布区的重叠率小于 5% 。我们推断, 重新定殖物种的种群增长率与其相较于已建群物种较低的建群数量有关, 并受到迁入和适宜栖息地选择的驱动。【翻译: 胡怡思; 审校: 聂永刚】.

暂无摘要。

Loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), nestlings were investigated through specimens found dead either after hatching or unhatched (n = 120) from eight nests around the Maltese islands (Central Mediterranean). Molecular genetics was used to conduct maternity and paternity tests of the collected specimens utilizing expanded mitochondrial DNA sequences from the control region (858 bp) and 25 microsatellite loci (12 dinucleotide loci and 13 tetranucleotide loci). Mitochondrial data produced two haplotypes, CC-A2.1 and CC-A3.1, with the most common haplotype being present in seven nests. Microsatellite data revealed the identity of six different females that were involved in the deposition of the eggs in the eight turtle nests analysed. This confirms that two females laid multiple nests. Additionally, microsatellite data allowed for the determination of multiple paternity, with one clutch being sired by two fathers. These results are useful for monitoring the genetic diversity of loggerhead sea turtle nestlings and of the turtle mothers and fathers contributing to future turtle offspring, which rely on Maltese sandy beaches for their successful start to life. Effective conservation management benefits from merging scientific knowledge with effective measures at potential nesting sites to avoid losses of nestlings caused by human negligence.

Dispersal patterns in primates have major implications for behavior and sociality but are difficult to reconstruct for fossil species. This study applies novel strontium isotope methodologies that have reliably predicted philopatry and dispersal patterns in chimpanzees and other modern primates to previously published strontium isotope ratios (87Sr/86Sr) of two South African hominins, Australopithecus africanus and Australopithecus robustus. In this study, the difference or \'offset\' was calculated between the 87Sr/86Sr of each fossil tooth compared to local bioavailable 87Sr/86Sr as defined by cluster analysis of modern plant isotope ratios. Large teeth (presumably belonging to males) have low offsets from local 87Sr/86Sr proxies, while small teeth (presumably from females) have greater offsets from local 87Sr/86Sr proxies. This supports previous conclusions of male philopatry and female dispersal in both A. africanus and A. robustus. Furthermore, A. robustus shows more extreme differences between presumed males and females compared to A. africanus. This is analogous to differences seen in modern olive baboons compared to chimpanzees and suggests that A. africanus may have had a larger home range than A. robustus. Neither hominin species has 87Sr/86Sr consistent with riparian habitat preferences despite the demonstrated presence of riparian habitats in South Africa at the time.

In eusocial invertebrates and obligate cooperative breeders, successful reproduction is dependent on assistance from non-breeding group members. Although naked (Heterocephalus glaber) and Damaraland mole-rats (Fukomys damarensis) are often described as eusocial and their groups are suggested to resemble those of eusocial insects more closely than groups of any other vertebrate, the extent to which breeding individuals benefit from the assistance of non-breeding group members is unclear. Here we show that, in wild Damaraland mole-rats, prospective female breeders usually disperse and settle alone in new burrow systems where they show high survival rates and remain in good body condition-often for several years-before being joined by males. In contrast to many obligate cooperative vertebrates, pairs reproduced successfully without non-breeding helpers, and the breeding success of experimentally formed pairs was similar to that of larger, established groups. Though larger breeding groups recruited slightly more pups than smaller groups, adult survival was independent of group size and group size had mixed effects on the growth of non-breeders. Our results suggest that Damaraland mole-rats do not need groups to survive and that cooperative breeding in the species is not obligate as pairs can-and frequently do-reproduce without the assistance of helpers. While re-emphasizing the importance of ecological constraints on dispersal in social mole-rats, the mixed effects of group size in our study suggest that indirect benefits accrued through cooperative behavior may have played a less prominent role in the evolution of mole-rat group-living than previously thought.

Reef manta rays (Mobula alfredi) are globally distributed in tropical and subtropical seas. Their life history traits (slow growth, late maturity, low reproductive output) make them vulnerable to perturbations and therefore require informed management strategies. Previous studies have reported wide-spread genetic connectivity along continental shelves suggesting high gene flow along continuous habitats spanning hundreds of kilometers. However, in the Hawaiian Islands, tagging and photo-identification evidence suggest island populations are isolated despite proximity, a hypothesis that has not yet been evaluated with genetic data.
This island-resident hypothesis was tested by analyzing whole mitogenome haplotypes and 2048 nuclear single nucleotide polymorphisms (SNPs) between M. alfredi (n = 38) on Hawai\'i Island and Maui Nui (the 4-island complex of Maui, Moloka\'i, Lāna\'i and Kaho\'olawe). Strong divergence in the mitogenome (ΦST = 0.488) relative to nuclear genome-wide SNPs (neutral FST = 0.003; outlier FST = 0.186), and clustering of mitochondrial haplotypes among islands provides robust evidence that female reef manta rays are strongly philopatric and do not migrate between these two island groups. Combined with restricted male-mediated migration, equivalent to a single male moving between islands every 2.2 generations (~ 64 years), we provide evidence these populations are significantly demographically isolated. Estimates of contemporary effective population size (Ne) are 104 (95% CI: 99-110) in Hawai\'i Island and 129 (95% CI: 122-136) in Maui Nui.
Concordant with evidence from photo identification and tagging studies, these genetic results indicate reef manta rays in Hawai\'i have small, genetically-isolated resident island populations. We hypothesize that due to the Island Mass Effect, large islands provide sufficient resources to support resident populations, thereby making crossing deep channels separating island groups unnecessary. Small effective population size, low genetic diversity, and k-selected life history traits make these isolated populations vulnerable to region-specific anthropogenic threats, which include entanglement, boat strikes, and habitat degradation. The long-term persistence of reef manta rays in the Hawaiian Islands will require island-specific management strategies.